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The lander removed enough dust from a solar panel to keep its seismometer on all summer, allowing scientists to study the three biggest earthquakes they have seen on Mars.
On September 18, NASA’s InSight lander celebrated its 1000th martian day, or ground, by measuring one of the largest and longest lasting earthquakes the mission has ever detected. The quake is estimated to be around a magnitude of 4.2 and shook for almost an hour and a half.
This is the third major earthquake detected by InSight in a month: on August 25, the mission’s seismometer detected two earthquakes of magnitudes 4.2 and 4.1. For comparison, a magnitude 4.2 earthquake has five times the energy of the previous mission record holder, a magnitude 3.7 earthquake detected in 2019.
The mission is studying seismic waves to learn more about the interior of Mars. Waves change as they travel through a planet’s crust, mantle, and core, providing scientists with a way to peer deep below the surface. What they learn can shed light on the formation of all rocky worlds, including Earth and its Moon.
The earthquakes may not have been detected at all if the mission hadn’t acted earlier in the year, as Mars’ highly elliptical orbit has moved it away from the Sun. Lower temperatures forced the spacecraft to rely more on its radiators to stay warm; this, added to the buildup of dust on InSight’s solar panels, reduced the power levels of the lander, forcing the mission to conserve power by temporarily shutting down some instruments.
The team managed to keep the seismometer on by taking a counterintuitive approach: they used InSight’s robotic arm to sink sand near a solar panel in the hope that when the wind gusts the transport through the panel, the granules remove some of the dust. The plan worked and during several dusting activities the team found that the power levels remained fairly stable. Now that Mars is approaching the Sun again, the energy is starting to come back little by little.
“If we hadn’t acted quickly earlier this year, we might have missed out on some great science,” said InSight principal investigator Bruce Banerdt of NASA’s Jet Propulsion Laboratory in Southern California, who heads the mission. “Even after more than two years, Mars seems to have brought us something new with these two earthquakes, which have unique characteristics.”
Temblor Insights
While the September 18 earthquake is still under study, scientists already know more about the August 25 earthquakes: the magnitude 4.2 event occurred about 5,280 miles (8,500 kilometers) from ‘InSight – the farthest quake the lander has detected so far.
Scientists are working to identify the source and direction in which the seismic waves traveled, but they know the tremor occurred too far to originate where InSight detected nearly all of its large earthquakes. previous: Cerberus Fossae, an area of approximately 1,609 kilometers. where lava may have flowed over the past millions of years. One particularly intriguing possibility is Valles Marineris, the epic canyon system that marks the Martian equator. The approximate center of this canyon system is 6,027 miles (9,700 kilometers) of InSight.
To the surprise of scientists, the earthquakes of August 25 were also of two different types. The 4.2 magnitude earthquake was dominated by slow low frequency vibrations, while fast high frequency vibrations characterized the 4.1 magnitude earthquake. The 4.1-magnitude quake was also much closer to the lander – only around 925 kilometers.
This is good news for seismologists: Recording different earthquakes at different distances and with different types of seismic waves provides more information about the internal structure of a planet. This summer, mission scientists used past earthquake data to detail the depth and thickness of the planet’s crust and mantle, as well as the size of its molten core.
Despite their differences, the two earthquakes in August have something in common other than being significant: Both occurred during the day, the windiest – and, according to a seismometer, the loudest – on Mars. InSight’s seismometer typically detects earthquakes at night, when the planet is getting colder and the winds are light. But the signals from these earthquakes were strong enough to soar above any noise caused by the wind.
Going forward, the mission team plans to do more dust cleanups after Mars’ solar conjunction, when Earth and Mars are on either side of the Sun. Because radiation from the Sun can affect radio signals, interfering with communications, the team will stop issuing commands to the lander on September 29, although the seismometer will continue to listen for earthquakes throughout the year. conjunction.
Learn more about the mission
JPL manages InSight for the Science Mission Directorate of NASA. InSight is part of NASA’s Discovery program, operated by the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and is supporting spacecraft operations for the mission.
Several European partners, including the National Center for Space Studies (CNES) and the German Aerospace Center (DLR), support the InSight mission. CNES provided the Seismic Experiment Instrument for the Interior Structure (SEIS) to NASA, with the principal investigator at the IPGP (Institut de Physique du Globe de Paris). Important contributions to SEIS came from the IPGP; the Max Planck Institute for Solar System Research (MPS) in Germany; the Swiss Federal Institute of Technology Zurich (ETH Zurich) in Switzerland; Imperial College London and the University of Oxford in the United Kingdom; and JPL. The DLR provided the heat flux and physical properties package (HP3), with important contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. The Spanish Centro de Astrobiología (CAB) provided the temperature and wind sensors.
Media contacts
André Good
Jet Propulsion Laboratory, Pasadena, California
818-393-2433
[email protected]
Karen Fox / Alana Johnson
NASA Headquarters, Washington
301-286-6284 / 202-358-1501
[email protected] / [email protected]
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